Intrusive may refer to:
Intrusiveness, a typically unwelcome behavior, interrupting and disturbing to others
Intrusive rock, intrusion of molten magma leaving behind igneous rock
Saltwater intrusion, the movement of saline water into freshwater aquifers
Intrusive thought, an unwelcome involuntary thought, image, or unpleasant idea
Linking and intrusive R, in phonetics
